Fluid pressure device



P 5, 1944. c. M. KENDRICK ETAL 2,357,334

FLUID PRESSURE DEVICE Orqiginal Filed March 29, 1941 3 Sheets-Sheet 1 INVENTORS CHARLES M. KENDRICK ATTORN EYS I S 5, 1944, c. M. KENDRICK ETAL' 2,357,334

FLUID PRESSURE DEVICE Original Filed March 29, 1941 3 Sheets-Sheet 2 IN 5 CHARLES MY P JQEICK BYHENRY EN P (1944- c. M. KENDRICK ErAL 2,357,334

FLUID PRESSURE DEVICE Original Filed larch 29. i941 s Sheets-Sheet s INVENTOR CHARLES M. KE RICK HENRY STEEN ATTORNEYS Patented Sept. 5, 1944 FLUID PRESSURE DEVICE Charles M. Kendrick and Henry Steen, New York, N. 1., assizno'rs to Manl Qorpm-ation, Washington, D. 0., a corporation of Delaware Original application March 29, 1941, Serial No.

Divided and this application December 28, 1943, Serial No. 515,926

'1 Claims. (Cl. 121 0.6)

This invention relates to rotary vane type fluid pressure devices, such, for example, as fluid motors or pumps, and more particularly to fluid pressure devices of this sort in which the rotor is provided with a plurality of vanes arranged to move inward and outward thereof, for example, in a substantially radial direction, during theoperation of the device. present application is a division of co-pending application Serial Number 385,820, flied March 29, 1941.

Fluid pressure devices of this general class find their widest use at present as hydraulic devices, that is, devices for handling or whose motive fluid is a liquid, such, for example, as oil, and the fluid pressure device of the present invention will be described in connection with such use. It will be understood, however, that the invention is applicable to fluid pressure devices operating with elastic fluids although it is particularly directed toward the provision of a practical, useful device suited for use as an hydraulic device for use in connection with relatively high working pressures, such for example, as 1,000 lbs. per sq. in.

Vane type fluid pressure devices of this character include a rotor having a, plurality of vanes movable inward and outward thereof, for example, in a substantially radial direction, and are provided with a vane track which is adapted to contact the exposed ends of the vanes and to control the inward and outward movement of the vanes. This vane track may comprise a vane track ring where the fluid pressure device is of constant capacity per revolution of its rotor or may comprise adjustable track members (such, for example, as shown in Patent No. 2,313,075 or in No. 2,313,246 or in co-pending application Serial Number 366,931, filed November 23, 1940) when the fluid pressure device is of the variable capacity type in which its capacity per revolution of it rotor can be varied. During operation of the device the vane track also cooperates with one or more of the vanes to radially separa e the high pressure fluid area on at least one of its circumferential ends, from the adjoining low pressure fluid area. The other circumferential end of the high pressure fluid area is also preferably defined by cooperation between another part of the vane track and one or more of the vanes, although this separation is sometimes effected by cooperation of a part of the vane rack and some other member of the rotary assembly, such as the rotor. It is essential that Y this cooperating contact take place between the fluid separating vane or vanes and vane track and it is also'essential that the ends of the vanes be in contact with the vane track as they move onto the portion of the vane track at which such separation occurs. It is also important and practically essential to maintain the exposed ends of the vanes continuously in contact with the vane track in order to obtain smooth, quiet and satisfactory operation of the device.

In fluid pressure devices which are operated as fluid motors or which are employed for other purposes requiring satisfactory operation at relatively low rotative speeds, it is therefore necessary that the vanes be acted upon (at least during the portion of their rotary movement in unison with the rotor in which the outer ends of said vanes move through the fluid intake areas) by a force sufllcient to move said vanes outward and maintain their outer ends in contact with the vane track.

Fluid pressure devices employing spring means for urging the vanes radially outward have heretofore been proposed but none of the proposals of which we are aware embodied a practical useful device meeting commercial requirements and particularly with respect to devices of this character for use with a substantially incompressible liquid, such for example, as oil as the circulated fluid, and for operation at relatively high pressures of the working pressure fluid, such for example as 1000 pounds per square inch or higher pressures. A

An object of the present invention is to provide an improved rotary vane type fluid pressure device including an improved, arrangement of cooperating elements whereby novel and improved spring means are practically and successfully employed for exerting an outwardly-active force on the vanes.

A er ject is to provide an improved fluid pressure device of this character that is capable of use, for example, either as a pump or as a fluid motor, that provides satisfactory operation at low rotative speeds as well as at speeds that are relatively high (such as 1200 R. P. M. and higher), that lssuited for operation at relatively low pressures of its working pressure fluid as well as at high pressures thereof such, for

- example, as 1,000 lbs. per sq. in., that stands up under use for long periods of time and that requires substantially no increase in size or decreasein capacity of the device as compared to the size and capacity of a similar vane type fluid pressure device in which no springs are employed to urge the vanes outward.

' A still further object of the invention is to provide a practical fluid pressure device of the character above mentioned which meets com- .mercial requirements and is suited for use with Other and more specific objects will appear I from the description which follows;

. ofithe vanes ll'as the-rotor revolves and to guide The invention will be understood from consideration of the accompanying drawings which illustrate, by way of example, the invention embodied in a fluid pressure device employed as a illustrative embodiment of the present invention taken along the line l-l of Figs. 2 and 3;

Fig. 2 is a view in vertical transverse section taken along the line 2--2 of Fig. 1;

Fig. 3 is also a vertical transverse sectional view but is taken along the line 3-4 of Fig. 1, looking in a direction opposite to that of Fig. 2;

Fig. 4 shows an inner elevation of one of the members, for convenience termed the "casing end plate" or "casing cheek plate";

Fig. 5 shows, in somewhat schematic arrangement, an inner elevation of a casing cheek plate modified for use in a reversible vane type fluid pressure device, together with a portion of the modifled fluid circuit employed therewith;

Fig. 6 is an enlarged fragmentary view, partly in section, taken along the line 8-6 of Fig. 2 and showing a face of one of the vanes together with the same vane spring therefor as illustrated in Figs. 1 and 2 but with the vane in or near its extreme radially outward position and with the vane spring correspondingly extended;

Fig. '7 is a side or end view of the vane spring illustrated in Fig. 6 as viewed from the right, drawn to substantially the same scale as that of Fig. 6 and with the vane spring compressed to the same extent as shownin Fig. 6;

Fig. 8 is a perspective view of the vane shown in Figs. 1, 2 and 6. drawn to substantially the same scale as that of Fig. 6;

'Fig? 9 is a view corresponding generally to Fig. 6 but showing a modification of the vane and the vane spring; and

Figs. 10 and 11 are likewise enlarged fragmentary views, partly in section, illustrating another modified form of the vane spring, in which Fig. 10 corresponds generally to Fig. 6 and Fig. 11 show the vane near its extreme radially inward position with the vane spring correspondingly compressed.

Referring now to the drawings, the motor includes a casing l0 formed with an open-ended cavity for the rotor is and associated parts as shown in Figs. 1 and 2. The rotor cavity is closed (Fig. 1) by an end head or cover member II which is attached to the casing In a b cap screws i2. The diameter of the rotor l5 illustrated is greater than the width or axial dimension thereof as may be observed in Figs. 1 and 2. The rotor is provided with a plurality of substantially radial vane slots l6 which extend from the fluid motor of constant capacity per revolution.

periphery of said rotor to a point intermediate 7 and control the vanes in their inward and outward movement; the surface 2. will hereinafter be referred to as the "vane track."

The rotor l5 and driven shaft 20 may be mounted and the two parts may be operatively connected with each other in any appropriate way. In the. present instance the rotor I I, shaft 20, their mountings and the operative connections therebetween are the same as disclosed in copending application flied December 8, 1939, Serial Number 307,755, since matured into Patent No. 2,335,284. As shown in Fig. 1 the shaft 20 is revolubly supported by a pair of bearing elements 23 and 24 carried by the casing l0 and the rotor I5 is mounted on the end of the shaft v 20 which projects into the rotor cavity. For this purpose the end of the shaft 20 is formed with axiall extending splines 2| (Figs. 1 and 2) and the rotor I5 is formed in its central opening with mating splines is (Fig. 2). The arrangement is such that the rotor i5 is freely movable in an axial direction on the shaft splines 2| while permitting a limited tilting or rocking motion of the rotor i5 relative to the shaft 20 in such manner that the cheek plates 34 and 35, to be presently described, determine the axial and angular positions of the rotor on the shaft and the plane of rotation of the rotor as fully explained in Patent No. 2,335,284, above mentioned.

The rotor I5 is hydraulically balanced with respect to all forces imposed thereon by pressure fluid in the embodiment illustrated. Balance of hydralic forces acting on the rotor in a radial direction is obtained by dividing the space intermediate the periphery of the rotor I 5 and the vane track 26 into two equal and oppositely positioned fluid sections, each fluid section comprising a working or pumping chamber flanked by an inlet and'an outlet area. As shown in Fig. 2, the division between the two fluid sections is effected by cooperation of the rotor i5 and the outer ends of the vanes I"| with the vane track 26 at the regions of the vane track's least diameter which in the present embodiment is adjacent the horizontal centerline. In the embodiment shown, the vane track 26 is provided at each of these points of division with an are 21, for convenience 4 termed the sealing arc, substantially concentric with the rotor l5, although not necessarily so, and extending in a circumferential direction for a distance equal to at least the angular distance between a pair of adjacent vanes I1.

The working or pumping chambers of the two fluid sections are formed by means of two diametrically positioned arcs 3| (Fig. 2), preferably concentric with the rotor i5 and termed the working arcs or pumping arcs, which are located in the regions of greatest diameter of the vane-track 26. Operating pressure fluid is admitted between the outer ends of the vanes as they move through the inlet areas toward the working chambers and fluid is discharged as the vanes recede therefrom through the outlet areas of the two fluid sections. The inlet area of each fluid section is thus at all times separated from the outlet area of that fluid section by at least one of the vane i1 and the difference in pressures on the opposite sides or faces of such vanes ass'nssa causes rotation of the rotor is of the motor. The portions of the vane track 23 intermediate the sealing arcs 21 and working arcs 3| may be given any suitable curvature producing satisfactory rates of inward and outward movement of the vanes l1 as the rotor l5 revolves.

A pair of mating disc-shaped members 34 and 35 (Figs. 1. 2 and 4), for convenience termed "end plates" or check plates, are disposed on the sides or axial. ends of the rotor I 5 and are provided with holes at their centers for the shaft 20. The cheek plates 34 and 35 perform several functions, one of whichis that they close the sides or axial ends of the working chambers; they also contain the ports for the admission of fluid to and exhaust of fluid from the inner and outer ends of the vanes l1, as will be more fully explained presently. The outer surfaces of the cheek plates 34 and 35 fit snugly against the wall surfaces of the casing I and end head ll respectively and form substantially fluid tight flts with the ports and passages in the casing to. The inner or opposing faces of the cheek plates 34 and 35 form fluid tight flts with the sides of the vane track ring 25 by which they are axially positioned with respect to the rotor l in such manner that the rotor is permitted to turn freely while its sides and the sides of the vanes l1 form substantially fluid tight running flts with the ad-' jacent faces of the cheek plates 34 and 35. The cheek plates 34 and 35 thus also serve as guiding surfaces for the sides or axial ends of the vanes i1 in their radially inward and outward movement and maintain the vanes in proper axial position with respect to the rotor as the rotor and vane assembly revolves. The cheek plate 34 will hereinafter be referred to as the casing cheek plate" and the cheek plate 35 will be referred to as'the end head cheek plate."

The cheek plates 34 and 35 are provided with coextensive ports (Figs. 1 and 4), the ports of one cheek plate being axially opposite the ports of the other cheek plate when the parts are in posi tion in the casing l0 so that all forces exerted upon the rotor l5 and vanes H in an axial direction by fluid pressure are thus balanced. The ports in the cheek plates 34 and 35 will be best understood from Fig. 4 which shows an inner elevation or the rotor face of the casing cheek plate 34. Each cheek plate is provided with a pair of diametrically opposed arcuate inlet slots or ports 36 and a similar pair of diametrically opposed ports or slots 31. The ports 36 and 31 of the casing cheek plate 34 are also partially shown in Fig. 2 and the ports 31 are also shown in the sectional view of Fig. 1. Operating pressure fluid is admitted to the outer ends of the vanes I1 through the pair of inlet ports 36 in the casing cheek plate 34, and similarly, fluid discharged or exhausted by the outer ends of the vanes l1 passes out through the pair of outlet ports 31 of the same cheek plate. The ports 36 and 31 of the end head cheek plate function principally as balance ports to contain fluid under the same pressure as that in the corresponding ports of the casing cheek plate 34 in order to produce balance of hydraulic forces acting upon the rotating parts, as already stated. Fluid may, however, also be admitted to and discharged from the inner ends of the vanes l1 through the ports 36 and 31 respectively of the end head cheek plate 35 as will be understood from the explanation which follows.

Each of the cheek plates 34 and 35 is also provided with two pairs of arcuate recesses or vane slot ports 33 and 33 which are positioned to register successively with the inner ends of the vane slots l3 as the rotor revolves. The vane slot ports 33 are connected with the inlet ports 33 by radial grooves or passages 40 on the outer faces of the cheek plates 34 and 35, as shown by the dotted lines of Fig. 4; the vane slot ports 33 are similarly connected with the outlet ports 31 by the radial grooves or passages H as shown by the dotted lines of Fig. 4 and by the full lines in the sectional view of Fig. l. The arrangement is such that the inner ends of the vane slots l6 are connected with fluid under the same pressure as that of the fluid acting upon the outer ends of their corresponding vanes l1 while said vanes are passing between the sealing arcs 21 and the working area 3|, and vice versa, and hence the vanes I1 are substantially in hydraulic balance when they are moving radially while passing along the intermediate portions of the vane track 26. The vanes l1 are thus substantially free to move radially inward and outward as they pass intermediate the sealing arcs 21 and working arcs 3|, so that vanes whose outer ends are passing through the inlet areas may be moved outward and kept in contact with the vane track by application of a force which is relatively small but is sufficient to shear the oil film, overcome friction, etc., and impart to each vane the required acceleration in a radially outward direction. In a vane type fluid pressure device of this character it is essential that the combined forces acting to urge each vane outward shall exceed the oppcsing force or forces acting to urge the vane inward during at least the portion of the rotary travel of the vane in which such vane must be moved outward in order to maintain its outer end in contact with the vane track. In most instances in which vane springs are employed to effect outward movement of the vanes, and particularly when the working pressure of the fluid is relatively high, this relation of forces acting to urge the vane inward and outward respectively is best obtained by maintaining at the inner ends of the vanes fluid pressure at least substantially equal to the pressure of the fluid simultaneously acting on the outer ends thereof during the time that said outer ends are moving through the inlet area or areas of the fluid pressure device; the importance of this will be more fully pointed out and explained'presently.

The vane slot ports 33 are here shown as made of such length that they also connect with the channel 43 which are formed in the casing Ill (Figs. 1 and 3). The fluid outlet channel 43 is connected with the outlet ports 31 of the casing cheek plate 34 as by slanted passages 41 (Figs. 1 and 3). and the fluid inlet channel 42 is connected with the two inlet ports 36 of said casing cheek plate 34 as by slanted passages 48 (Fig. 3) similar to the slanted passages 41. Working pressure fluid for operation of the motor is supplied through the inlet channel 42 by any suitable source, not shown,' and fluid discharged by the vanes I! as they rotate in unison with the rotor,

passes out through the outlet channel 43.

With the arrangement hereinbefore described "and with the parts in the position shown in Figs. 1 and 2, working pressure fluid admitted to the inlet channel 42 will pass into the inlet ports I! of the casing cheek plate 34 and the fluid inlet areas connected therewith; working pressure fluid acting on the adjacent faces of the vanes II that are then in contact with the working arcs 3i will cause rotation of the rotor and vane assembly and the shaft 20 in a counter-clockwise direction as viewed in Fig. 2. In order for this operation to take place, however, it is necessary that the outer ends of the vanes I! be in contact with the vane track 26 as said vanes approach the working area- 3i. As previously stated, it is also important and practically essential for quiet and satisfactory operation that contact between the outer ends of the vanes l1 and the vane track 28 be maintained throughout the movement of said vanes through the fluid inlet areas, as sudden and abrupt outward movement of the vanes would otherwise result and would produce noise, wear and unsatisfactory operation. This contact of the vanes I! with the vane track as they approach the working arcs 3| and the track-following action of the vanes as they pass through the fluid inlet areas will not dependably result, however, unless the vanes l1 are acted upon by an adequate radially outward force. According to the present invention this radially outward force is produced by improved means, including novel and improved vane springs, which will be described after-briefly considering some of the limitations and requirements obtaining.

One of the limitations is the very small amount of space available to accommodate each vane spring, which space limits and determines the maximum permissible size of the vane spring. For example, in one popular size of fluid pressure device in which no vane springs are used, the vane slots extend about radially into the rotor body, the rotor body is about 1" wide and the parallel opposing walls of each vane slot are spaced from one another a small distance such as %4" to so that the approximate dimensions of each vane slot is about A" x 1" x M or less. When vane springs are used this slot must accommodate both the vane and its vane spring because increase in dimensions of the vane slot to provide more space for the vane spring would in most instances require increase in the dimensions of the rotor and associated parts which is undesirable from the standpoint of size, weight, cost, operating and other considerations.

It is thus seen that the space available to accommodate each vane spring is very small, particularly when the vane is in its extreme inward position, and while the vane spring must be correspondingly small it must be capable of meeting severe operating requirements as has been broadly indicated previously. For example, each vane spring must be capable of relatively great deflection, particularly in comparison with its size. This deflection is due to the length of "stroke (1. e., the amount of inward and outward movement of the vane relative to the rotor) generally used and preferred for best efllciency: for example, the stroke of the vanes is usually from about to about in the fluid pressure device having the abovementioned vane slots. Moreover, the vane spring must be capable of performing its intended function, (i. e., moving the vane rad ally outward to'keep its outer end in contact with the vane track as the vane passes through the inlet areas) when the compression of the vane spring is least, that is to say, as the vane approaches its extreme radially outward positions adjacent the working arcs 3|; in fact, satisfactory functioning of .the vane spring at these regionsis absolutely essential as the outer end of the vane must be in contact with the vane track as it moves onto the working arcs 3| in order to provide satisfactory operation of the fluid pressure device.

From the foregoing it will be understood that because of its small size as indicated by the space available to accommodat it, each vane spring can exert only a relatively small force on its corresponding vane, particularly at the more critical points near its positions of least compression at which its functioning is of prime importance. In fact, the force that can be exerted by a vane spring meeting the operating requirements herein set forth is so small that said vane spring can perform its intended function (i. e., moving the vane outward during intake to keep its outer end in contact with the vane track) only when resistance to radial movement of the corresponding vane is reduced to substantially the minimum, so that the work to be done by the vane spring consists'merely of shearing the oil film, overcoming friction when the hydraulic forces acting on the vane are substantially balanced and imparting to the vane the necessary acceleration in its radial direction of movement. The importance of the previously stated relation as to relative pressures at the inner and outer ends of the vane during intake (1. e., that the pressure at the inner end of the vane shall be at least substantially equal to the pressure at the outer' end thereof during the time of its radially outward movement) thus becomes clear and the manner and extent to which it cooperates and contributes to a successful fluid pressure device of this character is also seen. It should also be noted, however, that substantial balance of hydraulic forces acting on the outer end of the vane as it passes through the inlet areas also contributes toward its freedom of radial movement and is of importance for this reason.

Balance of hydraulic forces acting on the rotor and vanes in an axial direction, 1. e., on the sides or axial ends of the rotor and vanes, which is provided by the mating slots in the cheek plates 34 and 35, as above explained, is also important as unbalance of these forces would tend to force the vanes against one or the other of these cheek plates and thus present resistance to inward and outward movement of the vanes in the vane slots.

Still another operating requirement of the vane spring grows out of the extremely large number of flexings required of each vane spring during the life of the device and the rapidity with which such flexings often occur. For example, in a fluid pressure device having two fluid sections as illustrated herein, each vane spring must flex twice for each revolution of the rotor; at 1200 R. P. M.,

' which is a speed often used commercially, each periods or continuous operation but must also have an almost indefinite life, as failure of a vane spring would not only result in noisy and unsatisfactory operation of the fluid pressure device but might also cause stoppage of the device if the broken spring became jammed between th moving parts and could also cause cutting and other damage to the parts even though no stoppage occurred.

As an indication of the small space available for the springs the illustrations of the spring seats and springs in Figs. 6 to 11 (i. e., in the scale 50 is of a novel and improved form of compound torsion-type spring, each comprising (Fig. 6) two substantially parallel arm or bar portions 5| and 54 respectively and two arm portions 52 and 53 respectively angularly disposed with respect to the arm portions 5| and 54 and with respect to each other. The contiguous ends of the respective arm portions are joined by coiled portions 55, '55 and 51 respectively, each preferably consisting of a plurality of coils, as best shown in Fig. 7, in order. that the stress incident to deflection of the vane spring 50 may be kept within desired limits. The arrangement is also preferably such that the coiled portions 55, 56 and 51 are substantially in alinement with each other as shown in Fig. 7, so that the outer coils of each of the three coiled portions lie in substantially the same planes. This may be accomplished in the forming of the vane springs and has several advantages among which is that each vane spring occupies a very small space when fully deflected without subjecting parts thereof to any appreciable alining forces that increase the stress. The arrangement also reduces the tendency of the parts of the vane spring to move out of line with one another as the spring is flexed, thus reducing the friction and wear between parts of the vane spring and the parallel opposing wall surfaces of the vane slot Hi. The proportions of the parts are also preferably made such that the coiled portion 56 comes within the recess at the inner end of the vane l1 and clears the adlacent inwardly projecting portion l9 thereof an arrangement that induces very little, if any,

localized stresses in said vane springs as they flex in unison with the inward and outward movements of the vanes; this is of great importance as such localized stresses could cause, and frequently would cause, failure of the vane springs and unsatisfactory operation of the device. The mounting and locating means for the vane springs are preferably made such that the vane springs are loosely disposed in the vane slots (that is to say, they are without definite attachment to the vanes, the. rotor or any other part of the device) and the arrangement is also preferably such that 7:;

limited self-locating or adjusting movement of the vane springs is permitted in order that said vane springs mayflnd and maintain their own operating positions. In the particular embodiments illustrated the foregoing are accomplished by a very simple arrangement which has proved entirely satisfactory in extended operation and which will now be described.

Each vane spring is maintained in operatin position by means of a recessed seat into which one of the ends of the corresponding vane spring is received and in the particular embodiment shown this seat is carried by the vane. For example, as best shown in Fig. 8, the radially inner end of each vane I1 is cut away to form a recessed seat It! for its corresponding vane spring 50. The seat |8 conveniently extends through the entire thickness of the vane and in the embodiment illustrated in Figs. 1, 6 and 8 said seat I8 is substantially straight, flat and parallel with the outer end ll of the vane l1 and is so arranged that a side portion IQ of the vane extends radially inward beyond said seat I8 when the vane I1 is in position in the rotor i5. The depth of the recess (i. e., the distance from the radially inner end-of the vane I! to the seat l8) may vary but is preferably kept small and, as illustrated, comprises a relatively small part of the vanes radial dimension; this is desirable in order to preserve the fluid seal intermediate the seat l8 and the periphery of the rotor l5, this seal being formed by the opposing wall surfaces of the vane slot l6 and the faces of the vane l1 and being of importance to prevent leakage from the vane slot ports 38 during the time that the outer endof each vane l1 moves across the working and sealing arcs. The relatively shallow depth of this recess further indicates the very small amount of space available to accommodate each vane spring as adready discussed. The arm portion 5| and coiled portion 55 of each vane spring 50 are disposed in the recess at the radially inner end of the corresponding vane l1 and parts thereof loosely engage and bear against the seat l8 which, together with the inwardly projecting portion l9, keep the vane spring in operating position in its vane slot. The ends of the seat 8 preferably terminate in curved portions i9 which extend onto the contiguous surfaces of the inwardly projecting portions IQ of the vane, these curved portions l9 preferably having a radius equal to or greater than that of the coiled portion 55 of the vane spring; this construction tends to assist the vane spring 50 in finding its proper operating position and is also of advantage from the standpoint of strength of the vane. The arrangement is also preferably such that the combined longitudinal dimensions of the arm 5| and coiled portion 55 of the vane spring are slightly less than that of the recessed seat l8 in order to permit but limit self-locating or adjusting movement of the vane spring in a generally longitudinal direction,

by simple retaining means disposed entirely within the corresponding vane slot l5. Moreover the vane spring 50 is kept out of contact with the opposing inner wall surfaces of the cheek plates of the cheek plates, particularly if any portion of the vane spring enters any o f the ports 35 and 31 or the vane slot ports 38 and 38.

Asalready stated, the arm portion and the coiled portion 55 of each vane spring continuously bear against the recessed seat I8 of the corresponding vane l1. Similarly, the arm portion 54 and the coiled portion 51 of the vane spring are arranged to loosely engage and continuously bear against the inner end or :wall l5 of the corresponding vane slot IS. The arm portions 5| and 54 are thus substantially parallel with each other when the parts are in position in the motor and they remain in this parallel relation throughout deflection of the vane spring 50 as the corresponding vane |1 moves radially inward and outward. There is thus a substantially unchanging contact relation be tween the coiled portion 55 and the arm portion 5| with respect to the seat l8 and likewise a substantially unchanging contact relation between the-coiled portion 51 and the arm portion 54 with respect to the innerend l5 of its vane slot 15. Further, there is also a substantially unchanging positional relation between the arm portion 5| and the coiled portion 55, and, similarly between the arm portion 54 and the coiled portion 51. These contact and positional relations assist in keeping the vane spring free from substantial localized stress.

The arrangement and construction of the vane spring 50 has a number of advantages. For example, it is a compound torsion-type spring, that is to say, it comprises at least two coiled portions which are active in torsion as the spring flexes and which are separated from one another by an arm portion. All three of the coiled portions 55, 55 and 51 of the vane spring 50 are active in torsion as the spring is flexed and there is a relatively small difference between the force exerted by said vane spring and the vane |1 when the vane is in its extreme outward position as compared with th force exerted by said spring on said 'vane when said vane is in its extreme inward position; the needed outward force is thus provided at all positions of the vane but without materially excess force, which could induce high stress in the vane spring 50, when the vane is in its extreme inward position. Another advantage is that there is little or no longitudinal movement of the arm portion 5| and coiled portion 55 and of the arm portion 54 and coiled portion 51 in their contacts with the seat l8 of the vane l1 and with the inner end ii of the vane slot l5 respectively as the vane spring is flexed incident to the inward and outward movement of the vane, with consequent little or no wear and friction at these points. A still further advantage is that the vane spring 50 exerts little or no end thrust on the corresponding vane l1 in a direction tending to move it against one of the cheek plates 34 or 35.

The vane type fluid motor hereinbefore described has many advantages, some of which sive yet provides dependable operation for long periods. Its operation is controlled by regulating, in any suitable manner, the volume of working pressure fluid admitted to its fluid inlet channel 42 and it will start smoothly and promptly when working pressure fluid is admitted to said channel 42. It operates quietly and steadily at speeds ranging from those which are very low to those which are relatively high, such, for example, as 1200 R. P. .M. and at working pressures up to relatively high working pressures, such, for example, as 1,000 lbs. per sq. in. It is capable of extremely rapid acceleration and deceleration due to the small size and weight of its rotating parts and the complete balance of hydraulic forces acting thereon: in fact, it can be accelerated from zero up to 1200 R. P. M. in a fraction of a second. In short, as demonstrated in actual practice, it provides operation that is entirely satisfactory and that is exceptional in certain characteristics. These operating properties are provided not by any single element alone but by the cooperation of th several elements as hereinbefore explained.

The arrangement above described also provides quick and easy assembly. In assembly, the shaftlll, casing cheek plate 34 and rotor l5 are first put in place in the usual manner. The vane and vane spring elements are then put in place: this is accomplished by putting the arm 5| and coiled portion into place in th recessed end of the corresponding vane l1 and inserting both of them together into the corresponding vane slot Hi, the vane spring 50 being compressed with the fingers sufliciently to permit its entry into said vane slot, The vane and vane spring elements can most conveniently be put into place when the corresponding vane slot I5 is opposite one of the working arcs 3|, the rotor l5 being rotated as necessary to provide in turn this relative position for each of the vane slots. When inserted in the above manner, the vane springs 50 flnd and maintain their own proper operating positions without further care or attention. In

' tical with the arm 54 and coiled portion 51 rehave been indicated. It is simple and inexpenspectively, these portions having been designated with different reference numerals for convenience in description: this arrangement facilitates assembly as no attention need be paid to which of these portions is put into the recessed end of the vane I1 and which of the portions bears against the inner end I6 of the corresponding vane slot IS. The vanes H are likewise preferably identical or symmetrical with respect to their two faces, so that either face of any vane may be employed as its leading face or vice versa. It is thus almost impossible to improperly assemble the vane and vane spring elements, which may be done quickly, without great care and with full assurance that the vane spring 50 will flnd their proper operating positions and give satisfactory results. The ease of assembly provided by this arrangement may also be understood from the fact that it'takes only a few minutes to insert the entire set of vanes and vane springs in the vane slots of a fluid motor of the character illustrated.

The vane type fluid motor as hereinbefore described is not reversible, that is to say, working pressure fluid must be supplied only to the fluid inlet channel 42 which causes the rotor l5 to revolve in a counter-clockwise direction as viewed. in Fig. 2. The arrangement may be readwhether working pressure fluid is supplied to the channel 42 or the channel 43, either of which may be employed as the inlet channel. By way of example, a modified arrangement for a reversible vane type fluid motor according to the present invention is diagrammatically illustrated in Fig. 5. Y

The modified casing cheek plate I34 of Fig. is provided with a pair of vane slot ports I38 corresponding generally to the vane slot ports 38 of Fig. 4 but arranged to connect with the inner ends of the vanes during only the time that the outer ends thereof are moving intermediate the sealing arcs 21 and working arcs 3I while passing through the fluid areas connected with the ports 36. The vane slot ports I38 are connected with the ports 36 as by grooves or passages 48 on the outer face of the end plate I34 so that the pressure in the ports and vane slot ports is substantially equalized. The modified casing cheek plate I34 also includes a pair of ports 38 and a pair of vane slot ports 38 which are connected on the outer face of said cheek plate I34 by grooves or passages 48, all identical with the similarly designated ports and passages of the cheek plate 34 of Fig. 4.

The rotor face of the casing cheek plate I34 is also formed with two pairs of recessed vane slot ports I32 and I 33 respectively which are disposed intermediate the vane slot ports I38 and 39 and are adapted to connect with the inner ends of the vane slots I6 during only the time that the outer ends of the vanes I6 therein are traversing the working arcs 3I and sealing arcs 21 respectively. In the particular embodiment illustrated the two pairs of vane slot ports I32 and I33 are arranged to be supplied with pressure fluid from whichever of the pair of ports 36 or 31 are at the time the inlet or high pressure ports; the ports I32 and I33 are accordingly connected, as by the schematically illustrated passages I39, with a passage I48 leading to a passage MI and connecting with said passage I4! at a point intermediate its ends. The ends of the passage I4I connect with a pair of oneway check valves I42 and I43 respectively which in turn are connected with the ports 36 and 31 respectively as by the passages I44 and I45. The one-way check valves I42 and I43 are arranged to permit the passage of fluid from the passages I44 or I45 into the passage I48 but prevent the passage of fluid in the opposite direction. With this arrangement, the passages I4I, I48 and I 38 and the vane slot ports I32 and I33 are at all times supplied with working pressure fluid from whichever of the pair of ports 36 or 31 are at the time the high pressure or inlet ports of the fluid motor. Working pressure fluid is thus provided to assist in holding the vanes H in contact with the vane track during the time that the outer ends thereof are traversing the working arcs 3I and sealing arcs 21, and this is true irrespective of whether the ports 35 or the po ts 31 are the high pressure or inlet ports. The pressure of the fluid acting on the inner and outer ends of the vanes as they pass intermediate the working and sealing arcs is substantially equalized, and this is also true irrespective of whether the ports 38 or the ports 31 are the inlet or working pressure ports of the motor.

Admission of working pressure fluid to the channel 42, and hence to the ports 36, causes the rotor I5 to revolve in a counter-clockwise direction as viewed in Fig. 2, as previously explained. Admission of working pressure fluid to the channel 43, however, causes the rotor, I5 to revolve in a clockwise direction as viewed in Fig. 2. The direction of rotation of the rotor I5 and shaft 28 may thus be reversed by reversing the direction of fluid flow to and from the channels 42 and 43 respectively.

A vane type fluid motor embodying the modified arrangement of Fig. 5 provides equally and entirely satisfactory operation in either direction of rotation of the rotor I5 and is capable of reversal, either slowly and gradually or very rapidly,'reversals at the rate of 3600 per hour having been made under inertia load.

The mating or end head cheek plate for use with the modified casing cheek plate I34 is, of course, correspondingly modified to provide an arrangement of its vane slot ports similar to and mating with the vane slot ports 39, I32, I33 and I38 shown in Fig. 5. It is sufllcient, however, to provide the check valve arrangement shown in Fig. 5 for only one of the cheek plates (i..e., for the ports I32 and I33 of either the casing cheek plate or the end head cheek plate, but not for both cheek plates) as working pressure fluid is supplied to the ports I32 and I33 of the other cheek plate through the inner ends of the vane slots I3.

Numerous other modifications may be made, as, for instance, in the construction and arrangement of the vane springs. For example, it is not necessary that the three coiled portions of the vane spring 58 have the same diameters. This will be understood from the modified compound torsion type vane spring 58' illustrated in Fig. 9 in which the coiled portion 56 is shown as having a diameter greater than that of the coiled portions 55 and 51. The use of a larger diameter for the coiled portion 56' does not require additional space for the vane spring as the other coiled portions are not in line therewith, relative to the radial position of the parts, and the larger diameter has the advantage of inducing less stress.

Fig. 9 also illustrates another practical modification, that is to say, the arm portions of the vane spring need not necessarily be substantially straight but may have other shapes, such, for example, as the curved arm 5| shown in Fig. 9. The vane II! of Fig. 9 is also modified to provide a curved seat II8 against which the arm 5! and coiled portion 55 are adapted to bear and on which they are free to move so that the vane spring 58 finds its own operating position, as in the embodiment previously described. The curved arm and vane seat arrangement illustrated in Fig. 9 permit a somewhat greater range of movement of the vane spring Si in finding its operating position than is the case in the arrangement of Figs. 1, 6 and 8. Vanes and vane springs of the arrangement of Fig. 9 have given entirely satisfactory operating results, but the curved vane seat requires a deeper out into the radially inner end of the vane than is required for the substantially straight vane seat I8 of Fig. 8, and the arrangement of Fig. 9 is therefore usually less desirable than that of Figs. 1, 6, '7 and 8 as well as for the reason of the somewhat greater time required in assembly, although the v latter is of minor importance.

tical and has proved successful and to which the present application particularly relates. For purposes of the present application the modified vane spring I50of Figs. 10 and 11 will be considered a employed in a reversible fluid pressure device, such, for example, as a reversible vane type hydraulic motor, including the modified cheek plate I34 and the modifled fluid circuit therefor as schematically illustrated in Fig. 5, although it will be understood that said vane spring I50 may also be employed in non-reversible fluid pressure devices which, for example, include cheek plates similar to the cheek plates 34 and 35 of Figs. 1, 2 and 4.

The vane spring I50 of Figs. 10 and 11 is a compound torsion type vane spring and comprises a pair of preferably identical arm portions I5I and I54 respectively having preferably identical coiled portions I55 and I51 respectively on one of the ends thereof. The coiled portions I55 and I51 are joined by an arm portion I52 extending between them in a generally diagonal direction and having a coiled portion I50 intermediate and preferably substantially equidistant from its ends; or, looked at from another view point, it may be said that a short arm portion I52 merges with and extends from each of the coiled portions I55 and I51 respectively with the two short arm portions I52 merging with a common intermediate connecting coiled portion I55. Each of the coiled portions I55, I56 and I51 preferably comprises a plurality of coils and said coils are also preferably arranged in substantial alinement with one another in the 'plane of their movement incident to flexing of the vane spring I50, as will be understood from the previous explanation of the vane spring 50 of Figs. 1, 6, 7 and 8. The proportions are also preferably such that the coiled portion I51 clears the adjacent inwardly projecting portion IQ of the corresponding vane I1 when the said vane is in its extreme radially inward position. With this arrangement the arm I5I is always parallel to the arm I54 but there is relative longitudinal movement between the arm I54, coiled portion I51 with respect to the arm I5I, coiled portion I55 as the vane spring I50 deflects in unison with inward and outward movement of the vane I1. This relative longitudinal movement usually takes place adjacent the arm I54 and coiled portion I51 at the inner end I8 of the corresponding vane slot I5 and in practice it has been found that this small longitudinal movement does not result in appreciable friction or serious wear, particularly when the inner ends II of the vane slots I6 are smoothly finished.

The arrangement of Figs. and 11 permits the vane spring I50 to be accommodated in a very small space and also permits the use of coiled portions having a diameter greater than that of the coiled portions of a vane spring of the arrangement illustrated in Figs. 1, 6, 7 and 8 for any given spacing of the recessed seat It from the inner end I6 of the corresponding vane slot I6. The intermediate coiled portion I55 may be omitted in some instances but its use has been found advantageous and vane springs of the general character illustrated in Figs. 10 and 11 have given entirely satisfactory results in extended operation.

While described as a vane type fluid motor, the fluid pressure device of the present invention will also function as a vane type pump. For example, use of the modifled arrangement of Fig. 5, as herein considered for p p ses of the aasasss present application, will provide a vane type pump capable of operation in either direction of rotation of its rotor, I5 and shaft 20; pressure fluid will be delivered into the ports 50 when the shaft and rotor are driven in a clockwise direction as viewed in Fig. 2 and into the ports 31 when said shaft and rotor are driven in the opposite direction. It will also function as a non-reversible pump when the arrangement is as illustrated in Figs. 1, 2, 3 and 4 and the shaft 20 and rotor I5 are driven in a clockwise direction as viewed'in Fig. 2, pressure fluid then being delivered into the ports 30. In either arrangement the modified vane springs I50 of Figs. 10 and 11 may be employed. In both arrangements, and with all forms of the vane springs illustrated, when used either as a pump or a motor the device will provide satisfactory operation at low'speed as well as at relatively high speeds such, for example, as 1200 R. P. M. or higher, and at working pressures up to 1000 lbs. per square inch or more and is particularly suited for use as an hydraulic device with a substantially incompressible liquid. such, for example, employed as oil, as the circulated fluid. The term fluid pressure device as used in the appended claims is therefore intended to include both pumps and motors as well as all other forms of fluid pressure devices to which the invention is applicable.

It is to be understood that the foregoing is merely an exemplifying disclosure and that changes, some of which have been indicated, may be made in the apparatus without departing from the applicants invention as defined in' the appended claims.

We claim:

1. In a rotary vane type fluid pressure device having a rotor provided with a plurality of vane slots, a vane in each slot arranged for inward and outward movement with respect to th rotor, a vane track adapted to contact the outer ends of said vanes and to guide and control said vanes in their inward and outward movement, a fluid inlet area positioned adjacent said vane track and said rotor whereby the outer ends of said vanes'are subject to the pressure therein while passin therethrough, means for substantially equalizing the pressure of the fluid simultaneously acting on the inner and outer ends of said vanes while the outer ends thereof are passing through said inlet area and spring means for moving said vanes outward to keep the outer ends thereof in contact with said vane track as they pass through said inlet area comprising a separate compound torsion-type vane spring for each vane, each vane spring having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm and flrst coiled portions having substantially unchanging contact with the inner end of the corresponding vane, a second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm and second coiled portions having substantially unchanging contact with the inner end oi. the corresponding vane slot, said first and second coiled portions being positioned adjacent the longitudinally opposite ends of said rotor, an intermediate arm portion projecting from each of said flrst and second coiled portions and extending toward each other in generally diagonal arrangement and an intermediate coiled portion merging with and disposed intermediate said intermediate arm portions.

2. In a rotary vane type fluid pressure device having a rotor provided with a plurality of vane slots, a vane in ach slot arranged for inward and outward movement with respect to the rotor, a vane track adapted to contact the outer ends of said vanes and to guide and control said vanes in their inward and outward movement, and a fluid inlet area positioned adjacent said vane track and said rotor whereby the outer ends of said vanes are subject to the pressure therein while passing therethrough, the combination of means for substantially balancing all fluid pressure imposed forces acting on said vanes while the outer ends thereof are passing through said inlet area and spring means for moving said vanes outward to keep the outer ends thereof in contact with said vane track as they pass through said inlet area comprising a separate compound torsion-type vane spring for each vane, each vane spring having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm and first coiled portions bearing against the inner end of th corresponding vane in substantially unchanging contact relation therewith, a'

second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm and second coiled portions bearing against'the inner end of the corresponding vane slot in substantially unchanging contact relation therewith, said first and second arm portions having substantially unchanging positional relations with respect to said first and second coiled portions respectively, said first and second coiled portions being positioned adjacent the longitudinally opposite ends of said rotor, and an intermediate arm portion projecting from said first and second arm portions and extending in a generally diagonal direction therebetween.

3. In a rotary vane type fluid pressure device having a rotor provided with a plurality of vane slots, a vane in each slot arranged for inward and outward movement with respect to the rotor, 21 vane track adapted to contact the outer ends of said vanes and to guide and control said vanes in their inward and outward movement, a fiuid inlet and a fluid outlet area for said device and spring means for moving said vanes outward as they pass through said inlet area comprising a separate vane spring for each vane, each vane spring having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm and first coiled portions bearing against the inner end of the corresponding vane in substantially unchanging contact relation therewith, a second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm and second coiled portions bearing against the inner end of the corresponding vane slot in substantially unchanging contact relation therewith, said first and second coiled portions being positioned adjacent the longitudinally opposite ends of said rotor, an intermediate arm portion connecting said first and second coiled portions and extending between them in generally diagonal arrangement and an intermediate coiled portion disposed intermediate the ends of said intermediat arm portion.

4. In a rotary vane type hydraulic motor for operation with a substantially incompressible liquid as the circulated fluid, a rotor having a plurality of substantially radial vane slots, a vane in each slot arranged for inward and outward movement in a substantially radial direction with respect tothe rotor, a vane track adapted to contact the outer ends of said vanes and to guide and control said vanes in their inward and outward movement, a fluid inlet area and a fluid outlet area adjacent the rotor, one of said areas being the high pressure area and the other of said areas being the low pressure area, the outer ends of said vanes being subject to the respective pressures in said areas while passing therethrough, an inlet port adjacent and connected with said inlet area, an outlet port adjacent and connected. with said outlet area, said ports being circumferentially spaced from one another by an arcuate distance equal to at least the angular distance between a pair of adjacent vanes, means for substantially balancing hydraulic forces acting on said vanes in substantially radial and axial directions throughout the time that the outer ends thereof are passing through said areas, means for maintaining at the inner ends of the vanes during the time that the outer ends thereof are moving circumferentially between said ports a pressure substantially equal to the pressure existing in the high pressure area, springmeans for moving said vanes radially outward while they are passing through the inlet area, said spring means comprising a separate vane spring for each vane, each vane spring having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm portion and said first coiled portion bearing against the inner end of the corresponding vane, a second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm portion and said second coiled portion bearing against the inner end of the corresponding vane slot, said first and second coiled portionsbeing positioned adjacent the longitudinally opposite ends of said rotor, an intermediate arm portion connecting said first and second coiled portions and extending between them in a generally diagonal arrangement and an intermediate coiled portion disposed intermediate the ends of said arm intermediate portion, each vane spring being disposed entirely within its corresponding vane slot, and means for maintaining said vane springs in substantially self-located operating position in said vane slots.

5. In a reversible rotary vane type fluid pressure device having a rotor provided with a plurality of vane slots, vanes in said slots movable inward and outward therein with respect to the rotor, a casing including a vane track adapted to contact the outer ends of the vanes and provided with a working chamber and a sealing chamber adjacent the rotor, each of said chambers extending in a circumferential direction for an arcuate distance substantially equal to the arcuate distance between two adjacent vanes and each of said chambers having interchangeable high and low pressure areas on opposite circumferential sides thereof adjacent the rotor, the outer ends of the vanes being subject to the respective pressures in said chambers and areas while passing therethrough, a pair of vane slot ports arranged to connect with the inner ends of the vane slots during the time that the outer ends 01 the corresponding vanes are passing through said areas respectively, fluid connections between said areas and said vane slot ports respectively, whereby fluid pressures acting on the inner and outer ends of said vanes are substantially equalized during the time that the outer ends of said vanes are passing through said areas, a third vane slot port arranged to connect with the inner end of the vane-slots during the time that the outer ends of the corresponding vanes are passing through the working chamber, a fourth vane slot port arranged to connect with the inner ends of the vanes during the time that the outer ends of the corresponding vanes are passing through the sealing chamber, means for supplying to said third and fourth vane slot ports fluid having substantially the same pressure as the pressure in the high pressure area irrespective of whichever of the areas is at the time the high pressure area and irrespective of interchange of relatively high spring means for moving said vanes outward to keep the outer ends thereof in contact with the vane track comprising a separate vane spring for each vane arranged to simultaneously and continuously react against the inner end of said vane and the inner end of the corresponding vane slot and having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm portion and first coiled portion being adapted to bear against the inner end of the corresponding vane, a second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm portion and second coiled portion being adapted to bear against the inner end of the corresponding vane slot, said first and second coiled portions being disposed adjacent longitudinally opposite ends of the rotor, an intermediate arm portion connecting said first and second coiled portions and extending between them in a generally diagonal arrangement and an intermediate coiled portion disposed intermediate the ends of said intermediate arm portion.

6. In a rotary vane type fluid pressure device having a rotor provided with a plurality of vane slots, a vane track and a fluid inlet area positioned adjacent the said vane track and said rotor, the combination of vanes in said slots, each of said vanes having a recess formed in the inner end thereof, the outer ends of said vanesbeing subject to the pressure in said inlet area while passing therethrough, and spring means for moving said vanes outward as the outer ends of said vanes pass through said inlet area, said spring means being in part unattachedly disposed in said recesses and maintained in substantially self-located operating position thereby, said spring means comprising a separate torsion-type vane spring for each vane, each vane spring having a first arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a first coiled portion, said first arm portion and first coiled portion being disposed within the recess of the corresponding vane and having a substantially unchanging contact relation with respect to said vane, a second arm portion extending in a generally longitudinal direction with respect to the rotor and merging at one end thereof with a second coiled portion, said second arm portion and second coiled portion having substantially unchanging contact with the inner end of the corresponding vane slot, said first and second coiled portions being positioned adjacent the longitudinally opposite ends of the rotor, and an intermediate arm portion projecting from said first and second coiled portions and extending in a generally diagonal direction therebetween.

7. In a. fluid pressure device of the rotary vane type, a rotor having vane slots and vanes disposed therein and adapted to follow a vane track, a torsion spring in each of said slots for assisting in holding the vane in contact with the track, each of said springs consisting of three elongated spring arms disposed generally in an axial direction relative to the rotor with adjacent arms merging into torsion coils, the inner end of each of the vanes and the inner end of each of the corresponding slots forming seats for the outermost and innermost arms of the springs, one of said seats being provided with an elongated recess disposed centrally thereof for receiving an elongated arm of a spring and stabilizing and centering the same and both said vanes and said inner ends of said slots being wholly unattached to the springs with the latter loosely engaging the same.

CHARLES M. KENDRICK. HENRY STEEN. 

